On Tuesday, the U.S. Patent and Trademark Office (USPTO) reaffirmed Microsoft's FAT patents (covering the File Allocation Table), but sources close to the Public Patent Foundation indicate that this is not the end of the story of efforts to overthrow these patents. According to sources cited by Linux-Watch.com, the re-issuance of the patent was based on the examiner's having accepted an argument previously advanced by Microsoft, and previously rejected.